Uint8Array Support for IE8

hacks.js

(function() {
  try {
    var a = new Uint8Array(1);
    return; //no need
  } catch(e) { }

  function subarray(start, end) {
    return this.slice(start, end);
  }

  function set_(array, offset) {
    if (arguments.length < 2) offset = 0;
    for (var i = 0, n = array.length; i < n; ++i, ++offset)
      this[offset] = array[i] & 0xFF;
  }

  // we need typed arrays
  function TypedArray(arg1) {
    var result;
    if (typeof arg1 === "number") {
       result = new Array(arg1);
       for (var i = 0; i < arg1; ++i)
         result[i] = 0;
    } else
       result = arg1.slice(0);
    result.subarray = subarray;
    result.buffer = result;
    result.byteLength = result.length;
    result.set = set_;
    if (typeof arg1 === "object" && arg1.buffer)
      result.buffer = arg1.buffer;

    return result;
  }

  window.Uint8Array = TypedArray;
  window.Uint32Array = TypedArray;
  window.Int32Array = TypedArray;
})();


(function() {
  if ("response" in XMLHttpRequest.prototype ||
      "mozResponseArrayBuffer" in XMLHttpRequest.prototype || 
      "mozResponse" in XMLHttpRequest.prototype ||
      "responseArrayBuffer" in XMLHttpRequest.prototype)
    return;
  Object.defineProperty(XMLHttpRequest.prototype, "response", {
    get: function() {
      return new Uint8Array( new VBArray(this.responseBody).toArray() );
    }
  });
})();

(function() {
  if ("btoa" in window)
    return;

  var digits = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

  window.btoa = function(chars) {
    var buffer = "";
    var i, n;
    for (i = 0, n = chars.length; i < n; i += 3) {
      var b1 = chars.charCodeAt(i) & 0xFF;
      var b2 = chars.charCodeAt(i + 1) & 0xFF;
      var b3 = chars.charCodeAt(i + 2) & 0xFF;
      var d1 = b1 >> 2, d2 = ((b1 & 3) << 4) | (b2 >> 4);
      var d3 = i + 1 < n ? ((b2 & 0xF) << 2) | (b3 >> 6) : 64;
      var d4 = i + 2 < n ? (b3 & 0x3F) : 64;
      buffer += digits.charAt(d1) + digits.charAt(d2) + digits.charAt(d3) + digits.charAt(d4);
    }
    return buffer;
  }; 
})();